$_ = 'I saw a saw saw a saw.
      Two to two to two two.
      Long long ago there lived a king.';

# !!! tf counting needs only a line 
$tf{lc $_} ++ foreach /\w+/g;  

foreach (sort {$tf{$b}<=>$tf{$a} }keys %tf)
{
	print "$_ : $tf{$_}\n" 
}
